Articles from reinforced plasticized polyvinyl halide resin

ABSTRACT

Compositions, composite articles and process for producing same are provided from a reinforced polyvinyl halide composition (A) comprising a high molecular weight polyvinyl halide resin, a plasticizer, and a reinforcement material, such as glass fibers, in combination with (B) a composition having adhesion to (A). Preferably (B) comprises a thermoplastic compound selected from the group consisting of PVC, plasticized PVC, styrene derivatives, urethane derivatives, acrylic derivatives, acrylonitrile derivatives, polyester derivatives, and mixtures thereof, with the most preferred composition being an unreinforced, plasticized polyvinyl halide composition. The composition article exhibits good strength, low sag at high use temperatures, and lowered coefficient of thermal expansion for use in contact with metal or polymeric substrates such as panels. The composition having a coefficient of thermal expansion not significantly different than the substrates in contact therewith, provides enhanced permanence of adhesion and sag resistance.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of co-pending Ser. No. 08/152,333filed Nov. 12, 1993, which is a division of Ser. No. 07/694,179, filedMay 1, 1991, now abandoned, which is a continuation-in-part of Ser. No.07/386,831 filed Jul. 31, 1989, now abandoned, which is a continuationof Ser. No. 07/099,818, filed Sep. 21, 1987, now abandoned.

This invention relates to plasticized polyvinyl halide resins reinforcedwith glass fibers, and articles made from such compositions.

Rigid polyvinyl halide resins, such as polyvinyl chloride are used forinjection molded or extruded articles. The PVC exhibits strength andcreep resistance at temperatures up to its glass transition temperature.To increase the stiffness or modulus of the PVC glass fiberreinforcement can be added. Low molecular weight PVC is chosen,particularly for injection molding applications because of theflowability.

Because high molecular weight PVC exhibits a higher viscosity, its usein injection molding is discouraged. It does not fill the moldsadequately because of its limited flow. This is unfortunate because thehigher molecular weight PVC exhibits better creep resistance attemperatures above the glass transition temperature of the material.Although the flowability of high molecular weight PVC can be improvedwith the addition of a plasticizer, this addition lowers the glasstransition temperature of the material. This lowering of the glasstransition temperature would indicate that creep resistance andstiffness at higher temperatures will be consequently lowered.

Although fiber reinforced rigid low molecular weight PVC exhibitsadequate flow in the molding process, higher strength at high usetemperatures is sought Therefore, new composition which would have thebalance of flow and higher strength at high use temperatures aredesired.

SUMMARY OF THE INVENTION

In one aspect, this invention is a polyvinyl halide compositioncomprising a mixture of polyvinyl halide resin, a plasticizer, and areinforcement material dispersed in the resin and plasticizer mixture.

In another aspect, this invention is an article prepared from theabove-described polyvinyl halide composition in a process wherein thecomposition is subjected to molding conditions.

In yet another aspect, this invention pertains to a composite of areinforced, plasticized polyvinyl halide composition (A) in contact with(B) a composition having adhesion to (A). Preferably (B) comprises athermoplastic compound with the most preferred composition being anunreinforced, plasticized polyvinyl halide composition. A process forproducing said composition and composite is also disclosed. Thecomposite can further comprise a component (C) selected from the groupconsisting of a metal article such as a steel or aluminum article eithercoated or uncoated as in an automotive body panel, a thermoset polymericarticle, and a thermoplastic article. Said component (C) is integrallybonded to at least one of the surfaces of (A) and (B). Said composite inthe elemental embodiment is comprised of component (A) integrally bondedwith (B). Component (A) comprises: a plasticized, polyvinyl halideresin, wherein said resin exhibits an intrinsic viscosity measuredaccording to ASTM D1243 of above 0.9, preferably said resin has anintrinsic viscosity of from 1.0 to 1.7 and most preferably said resinhas an intrinsic viscosity of from 1.0 to 1.4; a plasticizer present ata level of from about 15 weight parts to about 150 weight parts per 100weight parts polyvinyl halide resin in (A), preferably plasticizer ispresent from 20 weight parts to 55 weight parts per 100 weight panspolyvinyl halide in (A); and a fibrous reinforcing material selectedfrom the group consisting of glass mat, woven glass or non woven glassfibers, stainless steel shavings, polymeric fibers, such as aramid,polyamide, polymethacrylate, fibrous derivatives of cellulose and thelike. Component (A) can further comprise an elastomeric material, forexample, SBR, NBR, MBS, polyacrylate, ABS, urethane, copolyester,styrenic block rubbers and combinations thereof. Elastomeric materials,if present, are added in minor proportions with polyvinyl halide withoutdetracting from the physical properties of melt flow, storage modulus,and temperature sag resistance in (A).

The preferred reinforcement material is a high modulus material withglass fibers being the most preferred. Reinforcement material is presentin (A) at from 5 to 300 weight parts per 100 weight parts polyvinylhalide resin in (A), preferably reinforcement material is present from20 to 200 weight parts and most preferably present from 40 to 100 weightparts of reinforcement material per 100 weight parts polyvinyl halideresin in (A). Either said component (A) alone or said composite of (A)and (B) exhibit a storage modulus at 121° C. of from about 5.33 10⁶dynes/cm.² to about 1.33 10⁹ dynes/cm.², and preferably exhibit astorage modulus at 210° C. of from 1×10⁷ to 1×10⁸ dynes/cm.².

Component (B), in intimate contact with component (A) for the composite,comprises any material which will form a decorative and/or functionalcomponent in contact with at least one surface of (A). Alternativelycomponent (B) can include a coating, laminate or co-extruded materialproviding a surface and is further treated with a decorative materialsuch as a coating or paint. For instance, (B) can be a thermoplasticdecorative compound overlying (A) to provide a mar resistant finish, thecolor, texture or appearance being matched to suit the stylingpreference of the designer. Preferred materials comprising (B) arepigmented or unpigmented thermoplastic compounds having adhesion topolyvinyl halide surf aces and include PVC, plasticized PVC,, styrenederivatives, urethane derivatives, acrylic derivatives, acrylonitrilederivatives, polyester derivatives and mixtures of these composition incompounds recognized in the an for providing a functional and/oraesthetic appearance in contact with (A). Specifically, compositionscomprising styrene-acrylonitrile polymers, methacrylate polymers,aliphatic polyurethane as well as impact modified versions are suitablematerials for component (B). The most preferred material comprises aplasticized, stabilized polyvinyl halide composition absent said fibrousmaterial.

The composition and composite provide sag resistance at elevatedtemperatures as contributed by (A) and unexpected enhanced impactproperties as contributed by the combination of (A) and (B).

Despite the fact that adding the plasticizer to the resin lowers theglass transition temperature, the composition exhibits better strengthat 121° C. than rigid polyvinyl halide compositions which have higherglass transition temperatures. The plasticizer improves the flowabilityof the composition while the crystalinity of high I.V. polyvinylchloride and dispersed reinforcement material enhance the strength athigh temperatures. The compositions of this invention are useful in themanufacture of plastic molded articles requiring high use temperaturesunder low load conditions. Examples of such articles include windowsurrounds, automotive body side moldings attached to body panels, armrests and covers in automobiles, and in window frames.

DETAILED DESCRIPTION OF THE INVENTION

The polyvinyl halide polymers used in this invention are prepared fromvinyl halide monomer. Especially preferred polyvinyl halide polymers arepolyvinyl chloride polymers, and the remainder of the specification willdiscuss the aspects of the invention in reference to polyvinyl chloride.Any of the conventional processes for making such polymers such as mass,suspension, solution or emulsion polymerization can be used. Mass andsuspension polymerizations are the preferred processes. The process tobe described is a suspension process. When using the suspension process,suitable dispersing agents or suspending agents, such as known in theart, may be used. Examples of suitable dispersants are partiallyhydrolyzed polyvinyl alcohol, cellulose ether, starch, gelatin, and thelike. The level of dispersant used will be less than about 0.5 part byweight per 100 parts by weight of monomer. Excellent results areobtained with from 0.05 to 0.3 pan by weight of dispersant per 100 pansby weight of monomer.

The polymerization is initiated with a free radical catalyst Themonomer-soluble or oil-soluble catalysts that may be used in thepolymerization process to produce the polyvinyl chloride polymer used inthis invention are the alkanoyl, aroyl, alkaroyl, and aralkanoyldiperoxides and mono-hydroperoxides, azo compounds, peroxy ester,percarbonates, and other free radical type catalysts. As examples ofsuch catalysts, there may be named benzoyl peroxide, lauryl peroxide,diacetyl peroxide, diisopropylbenzene hydroperoxide, 2,4-dichlorobenzoylperoxide, naphthyl peroxide, t-butyl perbenzoate, di-t-butylperphthahte, isopropyl percarbonate, acetyl cyclohexane sulfonylperoxide, disecondary butyl peraxydicarbonate, 5-butylperoxyneodecanoate, di-normal propyl peroxydicarbonate,azo-bisisobutyronitrlle, a,a'-azodfisobutyrate,2,2'-azo-bis-(2,4-dimethyl valeronitrile), and many others. Theparticular free radical catalyst employed will depend upon the monomericmaterial(s) being polymerized, the molecular weight and colorrequirements of the polymer, the temperature of polymerization, etc.Insofar as the amount of catalyst employed is concerned, it has beenfound that an amount in the range of about 0.005 parts by weight toabout 1.00 parts by weight, based on 100 parts by weight of the monomeror monomers being polymerized, is satisfactory. However, it is preferredto employ an mount of catalyst in the range of about 0.01 part by weightto about 0.20 part by weight based on 100 part by weight of monomer(s).

The suspension polymerization process to produce the PVC polymers ofthis invention is carried out at any temperature which is normal for themonomeric material to be polymerized. Preferably, a temperature in therange of about 0° C. to about 70° C. is employed, more preferably fromabout 20° C. to about 55° C. In order to facilitate temperature controlduring the polymerization process, the reaction medium is kept incontact with cooling surfaces cooled by water, brine, evaporation, etc.This is is accomplished by employing a jacketed polymerization reactorwherein the cooling materials are circulated through the jacketthroughout the polymerization reaction. This cooling is necessary sincefree radical polymerization reaction are exothermic in nature. It isunderstood, of course, that a heating medium can be circulated throughthe jacket, if necessary.

Although the polymer can be a copolymer of the vinyl or vinylidenehalide and an ethylenically unsaturated monomer, it is preferred thatthe polymer or resin be a homopolymer of polyvinyl chloride.Homopolymers have physical crosslinks of high melting crystallites. Thepresence of high melting crystallites is evidenced by low sagging atelevated temperature by an unsupported sample under it's own weight.Polyvinyl halide homopolymers and copolymers which do not havesufficient levels of crystallites will exhibit poor elevated temperaturesag resistance and are not suitable for use in the present invention.Another way of differentiating from unsuitable Polyvinyl halidecopolymers for use in this invention pertains to the modulus ofelasticity and permanent modulus index of the copolymer. Copolymershaving a modulus of elasticity of less than 10,000 pounds per squareinch per ASTM-D747 and a permanent modulus index of less than 3,000pounds per square inch are not suitable for use in the presentinvention. Said permanent modulus index is defined as the 100% tensilemodulus of a composition containing 17 pans dioctyl phthalate perhundred parts of copolymer and is elaborated in U.S. Pat. No. 3,892,692.Such copolymers inherently possess inadequate strength above their Tg.

The presence of an appreciable level of randomly incorporated comonomerslowers the incidence of polyvinyl halide crystallites within thepolymer. Thus, homopolymers and copolymers which, in the compound formexhibit a degree of sag at 120° C. of greater than about 5 cm. using asample cantilevered 10 cm. from a horizontal support, are not suitablein this invention; sag being measured as the distance from a horizontalline parallel to the plane of the sample support and the unsupportededge of a 0.125 inch thick by 1.0 inch wide sample extending 4 inches(10 cm.) from it's fixed support, and measured after a 1 hour heat soakat 120° C. (method A). Random copolymers of a copolymerizable comonomersuch as an olefin present at 4 weight parts per 100 weight pans of vinylhalide monomer can have detrimental effects on the elevated temperaturesag resistance of the composition. Block copolymers of homopolymer PVCare suitable, provided the crystallites in the polyvinyl halide polymerare not substantially eliminated so that sag resistance as outlinedabove rises above about 5 cm at 120° C. after one hour.

The intrinsic viscosity (I.V.) as measured by ASTM D1243 is anindication of molecular weight and has been correlated with the minimumaverage molecular weight range for the polyvinyl halide polymerssuitable for use in the present invention. The polyvinyl chloridehomopolymers having an I.V. of above about 1.0, that is, 0.9 I.V. orabove, will have a sufficient crystallinity such that, in theplasticized state in combination with reinforcement the composition willprovide the minimum acceptable elevated temperature sag resistance. Thehigher molecular weight assists in building rubbery strength attemperatures above the glass transition temperature of PVC. Anypolyvinyl halide polymer with a molecular weight sufficient to provide aplasticized reinforced composition having a storage modulus at 121° C.of at least about 1.33 10⁷ dynes/cm.² is suitable. The molecular weightof a polyvinyl halide polymer within the suitable range may be selectedin relation to the amount of plasticizer or reinforcement to be added,but typically will be above about 1.0, that is, from 0.9 I.V. to 2.4I.V., preferably from about 1.0 to about 1.7 and most preferably from1.0 to 1.4 I.V.

The plasticizers useful in this invention are any of the conventionalplasticizers used with polyvinyl halides and in particular, polyvinylchloride. Included are plasticizers suitable for PVC and include thosetaught in The Technology of Plasticizers, Sears and Darby, John Wielyand Sons, New York (1982) ch.4, incorporated herein by reference. Asuitable plasticizer may be polymeric, or monomeric such as a high Tgsolid or a low Tg material, the preferred plasticizers being liquids.The amount of plasticizer employed is the minimum amount necessary toimpart a desired flow rate to the polyvinyl chloride composition asmeasured by spiral flow. Spiral flow is a measure of the extent ofinjection melt flow under a fixed work input and predicts limitations insize and configuration of injection molding dies suitable for a givenresin compound. The test employs a graduated 60-inch spiral flow moldwith a standard cross section die such as a 1/8 inch by 3/16 inchrectangular cross section die used in conjunction with a Arbug injectionmolding machine. Generally, the mold temperature is set at 55° C., theinjection melt pressure is constant at 27 psi with a 6-s injection time,18-s clamp time, and a 5-s mold open time, giving a total cycle time of29 s. A screw of 25 mm with L/D=18 was used. Stock temperature at thenozzle is standardized also. Spiral flow is proper when the polymer isable to flow into the pattern of the mold used. The extent of flow willvary depending on the molecular weight of the plasticizer, the molecularweight of the polyvinyl halide polymer as well as the mount ofreinforcement or other material employed. With the use of a relativelylower molecular weight polyvinyl halide polymer within the specifiedrange of I.V. a relatively lesser mount of plasticizer may be requiredto yield adequate spiral flow, while using a large mount ofreinforcement and/or filler may require the use of a higher mount ofplasticizer. It is desirable that enough plasticizer is added to imparta spiral melt flow in a 0.36 by 0.16 inch channel of above about 40inches, and preferably of from about 50 to about 70 inches. Typically,for the high molecular weight polymers contemplated for use in thisinvention, the mount of plasticizer can range from about 15 pans perhundred polyvinyl halide (resin) to about 100 parts per hundred resin,and preferably from about 20 pans per hundred resin to about 55 partsper hundred resin.

Examples of suitable plasticizers include the phthalates, epoxides,aliphatic diesten, phosphates and polyesters. Preferred are thephthalates and epoxides. Examples of preferred phthalates includedioctyl phthalate, diisooctyl phthalate, diisodecylphthalate; and mixedalkyl esters such as heptyl, nonyl and undecyl phthalate. Preferredepoxides include epoxidized soybean oil, and expoxidized linseed oil. Asused in the present invention, a single plasticizer can be employed, aswell as blends of different types of plasticizers. An example of apreferred blend is a blend of 85 pans per hundred pans resin of dioctylphthalate and 5 pans per hundred parts resin of epoxidized soybean oil.

The reinforcement material used in this invention is any material whichcan be mixed into and subsequently dispersed in the plasticizedpolyvinyl chloride mixture in a desired amount and which will notdetrimentally effect the flowability (e.g. spiral flow) of theplasticized polyvinyl chloride mixture but which will increase orenhance a physical property of the mixture at the use temperature.Preferably, the property increased is storage modulus, although improvedcreep resistance, and the like are also desirable improvements. Theamount of such reinforcement will vary according to the type used, themolecular weight of the polyvinyl chloride polymer, and the level ofplasticizer used. Typically, for the high molecular weight polyvinylchloride polymers and plasticizer level contemplated for use in thisinvention, the amount of reinforcement used to increase the storagemodulus can range from about 5 parts per hundred resin to about 300weight parts per hundred weight pans PVC resin, and preferably fromabout 20 weight parts to about 55 weight parts per 100 weight parts PVC.The most preferred amount of reinforcement material present is from 40to 100 weight parts of reinforcement material per 100 weight pans ofPVC.

Examples of suitable reinforcement materials sufficient to improvestrength include glass, either mat, woven or non woven fibers; stainlesssteel shavings; polymeric fibers, such as aramid or cellulosic fibers,and combinations of more than one of these. The preferred material isglass fibers. Alternatively glass fibers are present in addition to afiller such as calcium carbonate. In yet another alternative, glass,calcium carbonate and an elastomeric material are present. The mount ofglass used can range from about 5 percent to about 40 percent by weight,and preferably from about 10 to about 30 percent by weight.

The glass used in this invention can be sized or non-sized. A preferredsizing and coupling agent are disclosed in U.S. Pat. No. 4,536,360 toRahrig, incorporated herein by reference.

The plasticized reinforced polyvinyl chloride composition of thisinvention can also contain other additives such as pigments, fillers,impact modifiers, processing aids, lubricants, and the like. Suitablematerials which provide these function are known in the art.

To prepare the composition, it is desirable to first mix the amount ofplasticizer needed to provide the desired flowability with the polyvinylchloride resin and then add the amount of reinforcement material. As aresult of the mixing, the reinforcement material, whether initially inlong glass fibers or not, will be crushed and broken, and will bedispersed relatively uniformly throughout the mixture. The articles tobe made from the composition will generally be prepared at hightemperature under pressure. The temperature is high enough to fuse theresin particles, and the pressure is high enough to extrude an article,force the molten composition into the mold pattern, coextrude acomposite article, or co-inject the material with another component.Typically such temperatures range from about 175° C. to about 235° C.,and preferably from about 180° C. to about 210° C. The pressures aregenerally those encountered in inject/on molding and extrusion,co-extrusion, co-injection or laminating processes. The composition isalso useful in compression molding, although this process is not favoredas a commercial process.

The plasticized reinforced polyvinyl chloride composition hassubstantial strength under low load condition at high temperature. Itsstorage modulus at 121° C. can range from about 5×10⁶ to about 1.33 10⁹dynes/cm², and preferably from about 1.33 10⁷ to about 1×10⁸ dynes/cm².An alternative sag test, hereinafter Method B is similar to Method Aexcept that a sample strip 0.125 inch thick by 1 inch wide iscantilevered 1.5 inches (3.8 cm) from the horizontal support. Sag usingmethod B is expressed in degrees and measured as the angle between theplane tangent to the deflected surface nearest the tip of theunsupported sample and the horizontal plane parallel to the supportingsurface. Suitable compositions or composites of this invention exhibitless than 10°, preferably less than 5° and more preferably about 0° sagafter exposure to 120° C. for 30 minutes. The measured angle is takenfrom a line tangential from the deflected surface and a horizontal lineparallel with the undeflected surface, the cantilever distance being 1.5centimeters. Where sag is reported in terms of Method A, as outlinedabove, this represents the distance between the horizontal line takenalong the undeflected surface and the deflected edge of the sample thatis cantilevered 4.0 inches (10 cm) from the edge of the support. Thissag measurement under method A was taken at various temperatures rangingfrom 80° to 120° C.

The following examples illustrate the concept of this invention, but donot limit the scope of the claims.

EXAMPLE 1

A molding is prepared by injection molding from the followingingredients (unless stated otherwise, all pans are in pans per hundredresin):

    ______________________________________                                        Compound              Amount                                                  ______________________________________                                        A polyvinyl chloride homopolymer                                                                    100                                                     resin (intrinsic viscosity of 1.6)                                            Hycar ® 2301 × 120                                                                        8                                                       (Rubber process aid)                                                          Dioctyl Phthalate     85                                                      Barium/Cadmium        3                                                       (Heat Stabilizer)                                                             Calcium Carbonate     100                                                     Carbon Black          0.3                                                     Oxidized polyethylene 0.3                                                     (Lubricant)                                                                   Paraffin Wax          0.3                                                     (Lubricant)                                                                   Glass Fiber           33                                                      ______________________________________                                    

The PVC process aid, plasticizer, stabilizer, filler, pigment andlubricants are powder mixed in a Henschel mixer. The powder mixture isheated and sheared to a melt in Buss Kneader compounding equipment. Asecond port on the Buss Kneader is equipped with a feeding screw,through which the glass fibers are added. The melt and glass mixture issheared to uniformly disperse the glass throughout the melt. The mixtureis then pelletized, and this pelletized compound is then molded into0.125 inch thick bars at 200° C. melt temperature on an injectionmolding machine with a 75 ton clamp pressure. The mixture exhibits aspiral melt flow in a 0.16 inch by 0.36 inch channel of 55 inches. Themixture is cooled to allow it to solidify, and the following oven testis performed.

A 1.5 inch long 0.125 inch thick bar was placed in a clamp in an oven.After subjecting the piece to 121° C. for 30 minutes, the pieceexhibited 0° sag. The storage modulus of the piece at 121° C. is greaterthan about 1×10⁷ dynes/cm².

EXAMPLE 2

A second molding is prepared from the above-described composition in asimilar manner, except that 74 weight parts glass per 100 weight partsPVC are used rather than 10 weight percent The mixture exhibits a spiralmelt flow of about 46 inches. After subjecting a bar having the samedimensions as in Example 1 to 121° C. for 30 minutes, the bar exhibited0° sag. The storage modulus at 121° C. is greater than 1×10⁷ dynes/cm².

EXAMPLE 3

A composition was prepared by combining in a Henschel mixer 100 weightpans of a homopolymer PVC having an I.V. of 1.4, 10 weight pans of acrosslinked rubber used in the previous examples, 35 weight parts ofSanticizer® 711 believed to represent a mixed phthalate ester (C₇ -C₉-C₁₁), 3 weight parts of a dimethyl tin di-isooctylthioglycolatestabilizer, 0.3 weight parts carbon black, 0.5 weight parts of oxidizedpolyethylene, and 0.5 weight parts of paraffin wax. This mixture washeated and sheared to a melt in a Buss Condux kneader equipped with asecond port as in the previous example for introducing 64 weight partsof 10 micron (0.254 μm) diameter by 6.3 mm (0.25 in.) chopped glassfibers (Owens Coming Inc.). Glass fibers were thus introduced. Theuniformly fluxed mixture was pelletized. The pellets were molded into0.125 inch (3.18 ram) thick bars at 200° C. on a 75 ton injectionmolding machine.

The composition of example 3 will exhibit an adequate spiral melt flow.A six inch (15.2) by 0.125 inch (3.18 min.) thick molded bar was securedand cantilevered such that four inches (10 cm.) of sample extendedbeyond its support. Oven sag testing was performed at temperatures givenin Table 1 below.

EXAMPLE 4

A composition was prepared by combining in a Henschel mixer, 100 wt.parts of a homopolymer PVC having an I.V. of 1.4, 10 wt. parts of thecrosslinked rubber used in the previous examples, 40 wt. parts ofSanticizer® 711, 3 wt. parts of a dimethyl tin di-isooctylthioglycolatestabilizer, 0.3 wt. parts carbon black, 0.5 wt. parts of oxidizedpolyethylene, and 0.5 parts of paraffin wax. This mixture was heated andsheared to a melt in a Buss Kondux kneader equipped with a second portas in the previous example for introducing 66 wt. parts of 10 micron(0.254 μm) diameter by 6.3 mm (0.25 in.) chopped glass fibers (OwensCorning Inc.). Glass fibers were thus introduced. The uniformly fluxedmixture was pelletized. The pellets were molded into 0.125 inch thickbars at 200° C. on a 75 ton injection molding machine.

The composition of example 4 will exhibit an adequate spiral melt flow.A six inch (15.2 cm.) long by 0.125 inch (3.17 ram) thick molded bar wascantilevered such that four inches of sample extended beyond itssupport. Oven sag testing was performed for 1 hour at the temperaturesgiven in table I below.

COMPOSITE IMPACT PROPERTIES

The compositions of Examples 3 and 4 were heated in an oven and extrudedinto strips. The single layer strips were cut to size for testing. Othersingle layer strips (A) were hot laminated to a plasticized,unreinforced stabilized PVC film (B) and compression molded to simulatea co-extruded composite. The 2-layered (capped) strips and the untappedsingle layer strips were evaluated at room temperature (RT) forinstrumented puncture impact expressed as maximum force in pounds (N),peak energy and absolute energy in ft.-lb./in. (J/M). Instrumentedpuncture impact testing is based on drop dart impact test as in(ASTM-D2444). Testing of capped strips simulates the actual performanceof a fabricated composite useful for example in body side molding andbumper strips in particular, for the automotive industry.

    ______________________________________                                                 EXAMPLE                                                                       3            4                                                                uncapped                                                                              capped   uncapped  capped                                    ______________________________________                                        Max. Force 192       244      143     198                                     Lb. force (N)                                                                             (860)    (1085)    (636)   (880)                                  Peak Energy                                                                              29        33       21      33                                      Ft.-lb./in. (J/M)                                                                        (1547)    (1761)   (1120)  (1761)                                  Absolute Energy                                                                          59        73       51      65                                      Ft.-lb./in. (J/M)                                                                        (3148)    (3896)   (2721)  (3469)                                  ______________________________________                                    

As is noted from the above data, Examples 3 and 4 exhibit higherinstrumented puncture impact for the capped embodiment compared with thesingle layer, ie. uncapped strips. This is in contrast to a conventionalmulticomponent article of a thermoplastic over a metal strip. In such anembodiment, it has been observed that impact strength of a metalcore/thermoplastic composite is not greater than the impact strength ofthe metal component alone. In other words, the thermoplastic componentdoes not contribute to the design strength of the assembled article andthere is thus no synergy of strength enhancement between the metal andthe overlying thermoplastic. Whereas, in the present invention, directedto the above exemplified article, impact properties were consistentlyimproved for the thermoplastic composite as contributed to component (B)and seen in the impact strength of the capped strips. This wasunexpected.

COEFFICIENT OF LINEAR EXPANSION

The Examples 3 and 4 were extruded into strips and evaluated fordetermination of their coefficient of linear thermal expansion (COE) asexpressed in in/in °C.×10⁻⁵ (ASTM-D696) between -30° C. and +30° C. Inaddition, COE was measured at elevated temperature between +30° C. and+30° C. per the Test Procedures of the automotive Composite Consortium1990, Automotive Composite Consortium, Section 9.2.

    ______________________________________                                                       Example                                                                         3     4                                                      ______________________________________                                        COE.sup.1        1.7   1.5                                                    COE.sup.2        0.4   0.4                                                    ______________________________________                                        .sup.1 (-30-+30° C.) (in/in. · °C. ×             10.sup.-5)                                                                    .sup.2 (+30-+80° C.) (in/in. · °C. ×             10.sup.-5)                                                                    ______________________________________                                        Reference Materials--                                                         COE (in/in. · °C. × 10.sup.-5) between -30°      C. AND +30° C.:                                                        Steel                 0.8                                                     Aluminum              1.3                                                     Stainless Steel       1.9                                                     Glass reinforced Polypropylene                                                                      2.0                                                     Rigid PVC             6.5                                                     Polyphenylene oxide (PPO)                                                                           1.4                                                     ______________________________________                                    

It is noted the unexpected advantage of reduced COE for Examples 3 andbetween +30° C. and +80° C. Comparison with the reference materialsillustrates a desirable closer match between the COE of the metals andthe composite of the invention. This property is useful in articlesderived from the composite in contact with such materials. Thereinforced composite COE is lower than the COE for polypropylene, rigidPVC and similar to polyphenylene oxide engineering thermoplastic. Oneeconomic advantage therefore lies in the use of the composition of thepresent invention as compared to higher cost engineering thermoplasticssuch as PPO.

CO-EXTRUDED COMPOSITE

The composite of this invention can be co-extruded. This process isderived from the melt-forming of a multicomponent article from two ormore than two process streams, hereinafter termed co-extrusion for thesake of simplicity. The compositions of Examples 3 and 4 were eachco-extruded in a laboratory co-extrusion device to produce a 24 mm×2 mmcore reinforced strip (A) capped with an outer co-extruded un-reinforcedcap (B) of approximately 0.002 inches. The cores consisted of Examples 3and 4 compositions and the outer cap consisted of a flexible,un-reinforced, plasticized, stabilized PVC composition. Such a cap canthus be utilized as a decorative, weatherable, mar resistant componentand can be neutral, clear or formulated with colorants and/or pigmentsin addition to weatherability improving additives understood in the Art.

The preferred materials for (B) have advantages owing to the mutualadhesion between thermoplastics. This mutual adhesion is high for thepreferred plasticized PVC composition of (B) and obviates the need foradhesive means which are generally required to permanently adheredissimilar components. Owing to the sag resistance of the corereinforced plasticized PVC at elevated temperatures, the molded,extruded, co-molded or co-extruded article can withstand elevatedcontinuous use temperatures without sagging when attached to asubstrate, for example a metal panel at several discrete points.

In the conventional article, a metal core is combined with athermoplastic molding composition. A surface of the metal component, forexample, is attached or adhered to a panel by attachment or adhesivemeans respectively. One aspect of this invention resides in theattachment of the reinforced plasticized polyvinyl halide composition ora composite to a metal panel. The low COE at elevated temperature forthe composition is preferably not significantly different than the panelmaterial. This reduced difference in expansion allows for improvedpermanence of adhesion of the composition when adhered to a panel.Moreover, there is reduced stress between the composition and theattachment means which would otherwise create stresses in thecomposition leading ultimately to buckling distortion or adhesivefailure. This is a critical consideration where adhesive means are usedsince, at elevated temperatures there is typically a reduction inflexural modulus and static shear strength of adhesives. The increasedstress on the adhesive can be disruptive to the established bond andgreater failure of bonds and sagging of the article might result.Thermal expansion as well as sagging are greatly minimized by the use ofthe composite of the present invention. Attachment of the composition orcomposite to the panel material is enhanced along with weight savingsand improved design simplicity and reliability.

OVEN SAG RESISTANCE

Examples 3 and 4 were evaluated for sag by Method A at various elevatedtemperatures in an oven after a one hour heat soak. The samplecantilevered strips extended four inches (10 cm.) beyond the support.The distance was measured from the deflected tip to the height of thesupport.

                  TABLE 1                                                         ______________________________________                                                       Example 3 Example 4                                            Temperature    Sag (cm.) Sag (cm.)                                            ______________________________________                                         80° C. 0.4       0.5                                                   90° C. 0.6       0.6                                                  100° C. 0.8       0.6                                                  110° C. 1.5       1.0                                                  120° C. 1.5       1.4                                                  ______________________________________                                    

As can be seen in the oven sag results in Table 1, Examples 3 and 4molded plasticized reinforced compositions exhibit good sag resistance.It is preferred to achieve a sag resistance of less than about 5 cm.under these conditions, and most preferably, sag is less than about 2cm. for a 10 cm. cantilevered sample after 1 hour at 120° C. Bycomparison, for a rigid conventional molded fiber reinforced PVCcompound there is an upper limit on I.V enabling the minimumflowability. Such a rigid lower I.V. PVC even with a higher Tg wouldhave deflected completely, exhibiting no sag resistance (10 cm. sag) at120° C. The sag resistance exhibited by the compositions of thisinvention represents a significant strength improvement at temperaturesabove the Tg for the PVC composition. This evidences the criticalimportance of crystallites present in PVC which are not disrupted evenat which is a least 40 degrees Celsius (120° C.) above the glasstransition temperature. In addition, it is shown above that Example 4which contained 40 wt. pans of phthalate plasticizer compared to 30 wt.parts for Example 3, did not exhibit increased sag at elevatedtemperatures and is unexpected since the Tg for this example is lowerthan the Tg for example 3. This is a desirable feature relative to thecontribution of plasticizer for further enhanced processibility.

Various changes and modifications may be made in carrying out thepresent without departing from the spirit and scope thereof. Thesechanges are to be considered as part of the invention. While inaccordance with the Patent Statutes, the best mode and preferredembodiment has been set forth. The scope of the invention is not limitedthereto, but rather by the scope of the attached claims.

We claim:
 1. A fiber reinforced, plasticized polyvinyl halidecomposition, comprising:(a) 100 weight parts of a high molecular weighthomopolymer of polyvinyl chloride resin wherein said resin has anintrinsic viscosity per ASTM D-1243 of from 0.9 to 1.7; (b) from 20 to55 weight parts of a plasticizer per 100 weight parts of saidhomopolymer; and (c) from 5 to 40 weight percent glass fibers disperseduniformly throughout said composition, wherein after (a) and (b) havebeen combined and mixed, said glass fibers are added to the combinationcomprising (a) and (b) and wherein said composition in the compound formexhibits a degree of sag at 120° C. not greater than about 5 cm. using asample cantilevered 10 cm. from a horizontal support using a 0.125 inchthick sample.
 2. The composition of claim 1 wherein said plasticizer isa phthalate ester.
 3. The composition of claim 2 wherein the plasticizeris dioctyl phthalate.
 4. An article prepared by the process ofsubjecting the composition of claim 1 to temperatures sufficient to meltand fuse the polyvinyl halide resin, followed by cooling the article. 5.The article of claim 4, exhibiting a storage modulus of greater than1×10⁷ dynes/cm² at 121° C.